Electric switch



July 29 1924.

C. W. JAMESON 'ELECTRIC swITcH Filed Dec.. 1. 1920 2 Shura-sheet 1 July 29, 1924.

c. w. JAMESON ELECTRIC SWITCH Filed Dec. 1. 1920 Islands-Sheet 2 i ance elements are normall Patented July 29, 1924.l

UNITED STATES" CLARENCE W. JAMESON, 0F LOMBARD, ILLINOIS.

ELECTRIC SWITCH.

Application tiled December 1, 1920. Serial No. 427,612.

To all 'whom t may concern:

Be it known that I, CLARENCE W. JAME- soN, a citizen of the United States, residing at Lombard, in the county of Du Page and State of Illinois, have invented certain new and useful Improvements in Electric Switches, of which the following is a specication. L f

My invention relates to electrical switches, and more particularly to a motor-starting control-switch for Kautomatically effecting the gradual cutting out of resistance from the hne circuit in starting a moto-r.

Among the objects of my invention are to provide a controller switch employing a bodyor bodies of mercury as the shiftable circuit-opening-and-closing means in a. construction that may be small in size, of low weight, low cost, and high efliciency. Other objects of the invention areto provide for accurate timing lof the successive operations of cutting out resistance and to make the construction practically tamper-proof in this regard; to employ but `a small number of moving parts and attain effectiveness and v simplicity in the device. l

In thedrawings wherein I have illustrated a articular embodiment of my invention or purposes of disclosure, Fig. 1 is an elevation with parts in section, substantially on line 1-1 of Fig. 2; Fig. 2 is a cross-sectional elevation on line 2-2 of Fig. 1; Fig. 3 is a plan section of the movable switch-body showing a lwiring diagram therefor, the switch-section being takensubstantially on line 3 3 of Fig. 4;

Fig. 4 is a section on line 4-4 of Fig. 3'

showing the switch lblock in normal or open circuit position; and Fig. 5 is a similar.

view showing thek same tilted to closed-circuit position. v

In the drawings 10 indicatesnil suitable casing or housing for the assembledv parts, having an insulating strip 11 along its front through which extend the binding posts 12 for the connection of external wiring with the casing-contained wiring. Mounted in the casing are a tiltable mercuralswitch structure 13, an actuating magnet 14 for controlling its tilting movements, and a series of resistance elements 15. The general arrangement is such that the resistin circuit and magnetk 14 deenergized. en magnet 14 isv energized the switch is rocked thereby and sequentially, at proper intervals, shunts out the coils.

The resistance elements 15, to protect the -motor in. starting and thereafter be cut out the relatively-fixed contacts of the tiltable.

switch structure 13.

The switch structure 13 is preferably an oblong rectangular block internall chamlbered to hold mercury, and provi ed with relatively fixed contacts that extend into the mercury-receptive wells `in the interior thereof. It is pivotally mounted so that by tilting the block pivotally from normal inclination to reverse inclination the mercury runs into coacting relation to the relatively fxed contacts. Specifically, the block 13 has a lug 18 mounted on its bottom and extending well below the center of gravity of the block, this lug beingmounted on a longitudinal shaft 19 which finds bearing in the end walls of the casing. The block 13 may be rocked from the position shown in Fig. 4 to that shown in Fig. 5,

24 engaged with a pin 25 that is carried byl a prolongation of the stem or core 26 of the solenoid magnet 14, the magnet being mounted on a bracket 27 carried by the end wall of the casing.

It is preferred, in this general construction, that the weight of the movable parts.

is normally unbalanced, the preponderating weight ,of the switch block or element 13 being in rear of its pivotal axis 19 and the weight'of thev Solenoid core tending to hold the' switch normall iin the position shown in Fig. 4. The tiltlng of the switch element to the position-shown in Fig. 5 (and consequent shifting of the mercury within the acI . 5 position the mercury 'these chambers will immediately flood both switch-body) does not overcome this weightpreponderance that tends to place the switch in the normal position above-stated, with its front edge elevated.

As specifically illustrated, the switch block comprises a rectangular body portion 28 of insulating material, provided with suitable recesses, forming chambers or wells for the` reception of mercury and with passages for mercury-flow. This body is overlaid by a removable packing-sealed cover 29, making an air-tight closure of the several mercurychambers. As shown in Fig. 3 the fixed Contact members A to J extend through the front wall of the block, each having an external binding post portion 30 and an internal rounded acorn-shaped contact-stud portion 31, each stud being contained .in a bay or different one of the wells 32. As illustrated, the block is of construction to receive three separate bodies or masses of mercury M, these being respectively in the end mercury-chambers 34 and 35 and in the intervening main mercury chamber. 36, (the illustration of the mercury being omitted 'in' some views for clarity). Preferably, further, each mercury-mass has floated on it a body of lighter, non-inammable liquid, such as carbon-tetrachloride that is a good arc-suppressant, this body substantially iilling (save for a slight expansion-space) all the mercury-free space in the body. End chamber 34 opens directly and without restriction to the two wells or bays for the end contacts A and B, and chamber 35 is 'in the same relation to the contacts I and J, so that when the device is tipped to Fig. body in each 'of appurtenant contact-wells, bridging the intervening barrier and establishing connection through the mercury between the respective pair of contacts that form a double-makeand-break line switch. Of course on restoration to'normal position the mercury iows out of the contact wells, the tetrachloride of carbon N floating up to fill them and sup-- press any arcing-tendency.

The main mercury chamber 36 is preferably of triangular shape, with its base-to-V ward the rear and its apex communicating through supply duct 38, with that well containing contact H. This channel is preferably valved for adjustment of the rate of flow of mercury as by a screw 39 that is adjustable from the bottom of the block and that has its head covered by thel metal base plate 40, to which block 28 is screwed,r or by a sealing body 40 so that unauthorized change of the timing adjustment is made unlikely. The screw 39 may Work in a sleeve 39 through which a part of duct` 38 is drilled, this sleeve being molded fast into the Iinsulatingl block or body.

Each 'of the wells for the contact series H to C communicates lwith the one next to it by a suitably-small port 42, so thatv no material quantity of mercury will How into any well until all wells preceding it have been filled. Return ow passaves 43 lead back from the wells 32 to the base of triangular chamber 36. Thus, when the device, initially standing in rearwardly tilted position, with practically all of its main mercu body resident in main chamber 36 (as in icated by the mercury-level line in Fig. 4 is tilted to Fig. 5 position, the mercury ows at regulated rate through the valved supply duct 39, (only a very small quantity passing through passages 43) first lling the well for terminal I-I, then overflowing through port 42 into the well for terminal Gr, and so on throughout the series until it fills all of the wells and connecting passages for the contacts C to H.

As illustrated in Fig. 3 the construction described may appropriately be wired so that the motor supply line wires 50 and 51 are bridged by the high resistance solenoid 14 under the control of a hand switch 52. Upon the closing of switch 52 the solenoid is energized and the mercurial switch is rocked to circuit closing position. One line wire has connection to contact A and the other line Wire to Contact J. The motor O is connected between the contacts B and C, and between the contacts C and I are arranged the series-connected resistance coils 15, with taps 53 running from the several intervening contacts to connections between resistance coils, each contact that is sequentially brought into mercurial connection with its predecessor in the series cuts out one or more coils. As a matter of preference all taps from the coils are run to the binding posts 12 on the front insulating block 11, iexible connections 54 being made therefrom to the proper contact binding posts 30 of the thus insuring a rapid and effective makeand-break action with minimum tendency to arcing and with the break-occurring in an air-tight chamber preferably nearly lled with mert liquid. With respect to the resistance-controlling contacts of the central group, these are caused to cut out the resistance elements sequentially at a time in.

terval that may be very nicely regulated and that, once set, will be very accurately maintained.-

While I have herein describedfa specific embodiment o f my invention that I have found to be practical and eicacious, for

purposes of full disclosure thereof, it will be understood by those skilled` in the art that many changes' in detail might be made without departure from the spirit of my invention within the scope of the appended claims.

I claim:

1. In a motor-starting switch, a switch element mounted to rock to raise either sideedge above the other and comprising a body having therein a main mercury chamber having an apex toward one side edge of the body and its base ktoward the opposite edge, a plurality of wells sequentially connected disposed along said first edge and the first thereof receptively connected with theapex of said main mercury chamber, the connections between said wells being arranged to prevent the flow of mercury into one Well until all of the preceding Wells have been filled, respective return passages from the several wells to the base of said main chamber, contacts in said. wells, and a body of mercury, normally resident in said main chamber, adapted to flow yinto and till 'the connected wells when the switch element is rocked thereby to bring the said contacts successively into common connection.

2. A motor-starting switch comprising al body having a chamber, said body having a plurality of wells sequentially connected, the first of said wells being connected with said chamber, a plurality of contacts eachA located in one of said wells, a quantity of mercury located normally in said chamber and adapted to enter said wells in succession upon movement of said body t0 connect said contacts, the connections between said wells being arranged to prevent the flow of mercury into one well until all 'of the preceding Wells have been filled, and means for effecting a movement of said body to cause the flow of mercury into said wells.

3. A motor-starting switch comprising a body having a chamber, said body being provided with a series of connected wells, the first of said Wells being in communication with said chamber, a series of contacts each located in one of said Wells, 'a quantity of mercury located normally in said chamber, a series of individual return passages each leading from one of said wells to said chamber, and means for tilting said body to cause said mercury to iill said wells and connect said contacts, and to effect a reverse tilting whereby said mercury iiows back to said chamber through said return passages.

4. A motor-starting switch comprising a body having a chamber, said body having a plurality of wells sequentially connected, the connections between said wells being arranged to prevent the flow of mercury into one well until all of the 'preceding wells have-been filled, a regulable passage from said chamberto the first of said 'well.s,'a

plurality of contacts each respectively located in one of said Wells, a quantity of mercury located normall in said chamber and adapted to enter said wells in succession upon movement of said body, thereb to connect said contacts, and means for e ecting amovement of said body to cause the How of mercury into vsaid Wells.

5. In a motor-starting switch-structure, a tiltable switch element comprisin a body havin therein a seriesof sequentially connecte Wells, a main mercury chamber havmg an apex toward said Wells, a supply passage from said apex of said chamber to the first of said wells, and return passages from the other wells to the base of the mercury'chamber, contacts in said wells; a second, separate mercury chamber havin wells directly open thereto, contacts in sai Wells and mercury bodies in said chambers to f iow into and out of contact-connecting position according to the tilt of the element.

6. In a motor-starting switch-structure, a tiltable Switch element comprisin a body havin therein a series of sequentially connecte wells, a main mercur chamber having an apex toward said wel s, a supply passage from said apex of said chamber to the first of said wells, and return passages from the other wells to the base of the mercury chamber, contacts in said wells; a pluralit of other, separate mercury chambers each having wells directly open thereto, contacts in said wells and mercu bodies in said chambers to iow into an out of contactconnecting position according to the tilt of the element.

' 7. A tiltable switch structure comprising an insulating body and cover forming an elongated block, a pivotal support therefor having a longitudinal pivotal axis, said body having therein near one longitudinal edge a series of wells and having a main mercury chamber tapering to an apex and with its base toward -the opposite edge, a communication passage transversely of the body from the apex of said chamber to the rst Well, longitudinal communication ducts between pivoted axis, said body having therein near one edge a series of wells and having a main mercury chamber tapering to an apex and with its base toward the other edge, a communieation passage transversely of the body sages from said Wells to the base of the from the apex of said chamber t0 one W'ell, main chamber; contacts in the wells and a a screw-valve for regulating said passage mercury body normally resident in said 10 having its head covered by said base, longimain chamber adapted to ll the Wells when 5 tudinal communication duets between the the structure is tilted.

portions of the several Wells remote from the block-edge, and transverse return pas- CLARENCE W. JAMESN. 

